Clamping device



Nov. 21, 1950 G. MOFARLAND CLAMPING DEVICE Filed April 24, 1947 m y mpmw M m 7W5 my I Patented Nov. 21, 1950 CLAMPIVNG nnvrcn George L, McFarland, Scotia, N. Y., assignor to General Electric Company, a corporation of New York Application April 24, 1947, SerialNo. 743,687

3 Claims; (01. 188 -166) My invention relates to clamping devices, and more particularly to automatically operable, manually releasable clamping means for control a paratus of 'the type including an adjustable disk or dial,' or the like.

The invention has for its principal object the provision of a new "and improved'clamping device of the. abovetybe which, while simple and inexpensive tomanufacture, is positive and reliable in operation andjnot subject to slippage under shock or severe vibration.

My invention itself will'be more fully understood and its varicus'objects and advantages further appreciated bylreferring now to the following detailed specification, 1 taken in conjunction with the accompanying "drawing," in which Fig. '1 is a front jlview of a rotatable; dial and clamping mechanism embodying my invention; Fig. 2 is an enlargedjfragmentary vliewsimilar to Fig. -l but showing" the clamping mechanism.

.partly in section; and Figs. '3"an'd 4-are crosssectional views taken along the line 3-4 of Fig. 2 and showing the clamping mechanism in its clamped and unclamped positions, respectively.

Referring now to the drawing, I have shown my clamping device applied to a rotatable disk or indicating plate I, which may, for example, be the adjustable dial of a potentiometer,iavariable capacitor-or other suitable control apparatus.

The dial l is positioned in substantially parallel spaced relation with respect to a statlonary supporting panelTuponwhich is-mo'unted a clamping device 3 'arrangedto engagethe dial-in clamps... .ur.

The clamping-device 3-is mounted upon 'a 'base plate 4 fixed to the panel 2, as by a pair of bolts 5. Bolted to the upper end of the base plate 4, as by a pair of bolts 8, are two clamping blocks 1, between which are firmly and fixedly clamped two fiat, elongated resilient clamping members 8. The clamping members 8 are mounted contiguously in cantilever fashion between the blocks 1 and extend downwardly in substantially parallel spaced relation with the panel 2. In the illustrated embodiment of the invention the members 8 extend downwardly in flatwise engaging relation with each other for the greater portion of their length, though such engagement is not essential. The lower or free ends of the elongated clamping members 8 diverge slightly and are biased apart, the dial I being positioned between the diverging ends of the clamping members.

In order to press the clamping members 8 into clamping engagement with the dial I, I provide an L-shaped clamping plat? r slider 9. The

L-shaped plate -9 is rockably or pivotally mounted in spaced apertures I!) in the base plate l, and is disposed with one leg substantially perpendicular to the panel 2, the other operating leg being in substantially parallel spaced relation with the panel 2 and in front of the elongated clamping members 8, said operating leg providing-a surface substantially parallel to said dial and adapted to receive pressure in a direction substantially perpendicular to said surface from an operating outside source on the indicating, side of said dial. The lower leg of the L-shaped plate 9 is apertured or slotted, as at H andfits over the diverging end portions of the elongated clamping members 8. Thus, as. pressure is applied to said operating leg, the clampingplate .9 is rocked on the baseplate 4 between the positions shown at Figs-3 and 4, the apertured lower leg of the plate sliding along the clamping members 8.- The width of the apertureor slot H in the plates is such that, when the clamping plate is moved upward toward the fixed ends of the clamping members 8, it fits loosely over the members' 8, whereas when it is moved downward toward the diverging ends of the clamping memlo ers 8, it presses the members 8 together andinto "clamping engagement with the dial l positioned "therebetween.

plate 9 at the opposite end. The spring 12 norrhally! presses theplate 9 downwardly; thereby to hold the clamping members-8 inclampingposition. If it is desired to release the dial I, the upwardly extending front operating leg of the plate 9 is pressed inwardly, as at Fig. 4, thereby to slide the lower leg of the plate 9 upwardly and to release the clamping pressure on the dial.

It may now be noted that my improved clamping device is normally biased into clamping position, so that in order to move the dial, it is only necessary to release the clamp, as shown at Fig. 4, and adjust the dial as desired. When the operator removes applied pressure from the clamping plate 9, the spring l2 automatically reclamps the dial at the desired position. Moreover, it is an outstanding feature of my invention that shock or vibration not only has no tendency to loosen or release the clamping force, but actually permits the clamp to tighten its hold upon the dial I. This effect is due to the fact that the slight relative motion of the parts due to vibra- 3 tion allows the spring [2 to become more efiective to push the slider 9 farther down on the clamping members and thereby tighten their grip upon the dial l.

While I have described and illustrated only a preferred embodiment of my invention by way of example, many modifications will occur to those skilled in the art, and I therefore Wish to have it understood that I intend in the appended claims to cover all such modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a clamping device for a rotatable dial, a supporting panel disposed in substantially parallel spaced relation with said dial, a pair of elongated resilient clamping members mounted upon said panel at one end in substantiallyparallel contiguous relation and having their opposite ends-adapted to be disposed on opposite sides of said dialand biased apartin slightly diverging relation, an L -shape d clampingplate havingone leg apertured and fitting over the diverging portions'of'said'clamping members and the other serving as an operating leg extending along said clamping members in substantially. parallel spaced relation, means for pivotally mounting said clamping plate upon a portion of said panel acting-as-a-fulcrumat the end of said apertured leg to provideforsliding movement of said aperturedleg alongthe diverging portions-of said clamping members as said operating-leg of said plate is'moved toward and away: from said panel, said plate fitting loosely over said clamping members When-at one end of said diverging portions and pressing said clamping members into clamp"- ingrelationwith said-dialwhen moved toward the diverging endsof saidclamping members, and a compression spring encircling said clamping members and disposed-between a fixed seat at one end'andsaid clamping plate at the other end, thereby tobias'said clamping plate tohold saidclamping members in clamping position;

2; In a clamping device for a rotatable indicatingdisk, a base, a'pair of elongated clamping members mounted upon said base in substantially parallel contiguous relation and having slightly diverging end portions adapted to embrace said disk, a clamping plate having an apertured leg substantially perpendicularly connected to an operatingleg providing a surface substantially parallel to said disk and adapted to'receive operating pressure in a direction substantially perpendicular to said surface from an operating source on said indicating side of said disk, said apertured leg fitting over said diverging portions of said clamping members and rockably mounted at one end upon a portion of said base acting as a fulcrum thereby to permit sliding movement of said plate along said diverging portions, the aperture in said plate being of such width that said plate fits loosely over said clamping members when at one end'of said diverging portions and presses said clamping members into clamping relation with said disk when moved toward the other end of said diverging portions, and a compression spring encircling said clamping member and disposed between said base at one end and said apertured leg at the other end, thereby to bias said plate to a position to hold said clamping members in clamping position, said clamping members releasing said disk only when said operating pressure is applied to said surface of said operating leg.

3. In a clamping device for an adjustable indicating plate, a base, a pair of elongated clamping members mounted upon said base in substantially parallel contiguous relation and having slightly div'erging'end portions adapted to embrace said indicating plate, an apertured clamping plate fitting over the diverging. portions of said clamping members and rockably mounted at one end upon a portion of said base acting as a fulcrum thereby to permit sliding movement of said clamping plate along said diverging portions, the aperture in .saidnclamping plate being of such width that said clamping plate fits loosely over said clampingmembers when at one end of said diverging portions and presses said clampingmembers-into clamping relation with said indicating plate when moved toward the other end of said diverging portions, and a compression spring encircling, said clampingmember and dis posed between. said base at one end and said 40 clamping plate at the other end, thereby to-bias said clamping, plate to a position to hold-said clamping members in-clamping position.

GEORGE L. McFARLAND.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

